抄録
Austenitic stainless steel pipes made by centrifugal casting have been used as burner material for heat-treatment furnaces and other industrial furnaces. This material has a high heat resistance, but brittle fracture can occur earlier than expected. Brittle fracture may start in the final solidification layer with micro cavitated structure formed on the inner surface of centrifugally cast pipes during manufacturing. In the present study, the strength of the specimens of an austenitic stainless steel machined from centrifugally cast pipes was studied with attention to the final solidification layer on the inner surface of the pipe. The strength decreased with increasing area of the final solidification layer. In order to predict the fracture strength of pipes with solidification layers under a variety of yielding scales, two-parameter method was proposed based on the combination of the stress intensity factor criterion and the gross sectional yielding stress criterion.
